1. Field of the Invention
The present invention relates to a location board used in locating a covering member to a foam cushion member during assemblage of an automotive seat.
2. Description of Prior Art
The assemblage of an automotive seat entails bonding a covering member to the surface of a foam cushion member. There has been practiced the use of a location board for locating and retaining the covering member at a given position upon the foam cushion member, which is known, for example, from the Japanese Utility Model and Patent Laid-Open Pubs. Nos. 3-335995 and 62-181086, and the U.S. patent appln. No. 686,157. A typical conventional seat assemblage using such location board is illustrated in FIGS. 1 through 5.
FIG. 1 schematically shows the assemlbing steps for bonding a covering member (1) to the outer surfaces of a cushion member (2) by means of an upper die (5), a lower die (4) and location board (30).
As shown, the lower die (4) has a working surface formed in a shape generally conforming to the outer configuration of the foam cushion member (2), and that working surface of lower die (4) is provided with securing portions (4a). The covering member (1), which is to be secured upon this working surface of lower die (4), is formed such as to define therein a central seating cover section (11), peripheral cover sections (12)(12) sewn with the central seating cover section (11), and lateral cover section sections (13)(13). The peripheral cover sections (12)(12) are jointed at (1a) by sewing with the peripheral ends of central seating cover section (11) via a location board (3). The thus-formed cover member (1) is turned upside down and placed upon the lower die (4), with the sewn jointed portions (1a) of cover member (1) being secured in the securing portions (4a) of lower die (4). Hence, the cover member (1) exposes its reverse surface upon the lower die (4) for bonding with the foam cushion member (2). The cushion member (2) is formed such as to define therein a central seatting area (22) and a peripheral bolster areas (21)(21) surrounding the central seating area (22), each of those areas (22)(21) corresponding respectively to the central seating cover section (11) and peripheral cover sections (12). In the cushion member (2), there are formed recessed grooves (23)(23) at the respective junctures or boundaries between the central seating area (22) and peripheral bolster areas (21)(21). The flat bottom portion of the cushion member (2) is secured upon the upper die (5). Then, by lowering the upper die (5) towards the lower die (4), the outer surfaces of cushion member (2) are pressed against and bonded to the reverse surfaces of cover member (1). (of course, an adhesive has been applied to the outer surfaces of cushion member (2)) At this moment, both location boards (30) and sewn jointed portions of cover member (1) are inserted and bonded into the recessed grooves (23)(23).
With a particular reference to the location boards (3) and sewn jointed portions (1a) mentioned above, it is seen from FIGS. 2, 3 and 4 that the location board (3) is so formed as to have, defined therein, a first half part (30), a second half part (31) and a boundary line (not shown) defined those first and second half parts (30)(31). Although not shown and as known in the art, such boundary line is made smaller in thickness than the other planar area, for a cutting purpose to be explained later. Designation (33) denotes a notched portion of generally "U" shape, which is formed at the forward edge (33b) of location board (3), defining a cutting introductory point from which the two half parts (30)(31) are cut apart from each other. The notched portion (33) extends a very short distance (L2)(for instance, not more than about 3 mm) from that forward edge (33b) of location board (3) toward the inward area of the same, as viewed from FIGS. 4 and 5.
As shown in FIG. 4, one terminal end of the central seating cover section (11) and one terminal end of the peripheral cover section (12) are sewn together at the respective opposite sides of foregoing first half part (30) by two sewing threads (32)(34). In this respect, the FIG. 4 depicts the location board (3) to project from between the central and peripheral cover sections (11)(12), but as indicated by the hatching therein, those two cover sections (11) (12) are shown to be cut intentionally for the sake of highlighting the location board (3), and therefore it it to be understood that both cover sections (11) (12) expands their respective areas up to a line extending along the location board forward edge (33b).
Designation (32a) in the location board stands for an imaginary sewing line along which the sewing thread (32) is sewn to the juxtaposed three layer of central cover section (11), first half part (30) of location board (3) and peripheral cover section (12), in a manner penetrating therethrough at a given interval (L1) (corresponding to a sewing pitch of sewing machine used; say, approx. 5 mm) that can be seen from a series of equidistant resultant sewing holes (32-1, 32-2 . . . ). As viewed from FIG. 4 and 5, those sewing holes are rowed, starting from the forward edge (33b); namely from the forward edges of three juxtpoased elements (3, 11, 12) and extending along the longitudinal direction of the imaginary sewing line (32a). It is noted here that the aforesaid notched portion (33) also extends along such longitudinal direction of sewing line (32a), whereupon, only at that particular notched portion (33), there are sewn directly together the two cover sections (11)(12) of covering member (1) as indicated by the first sewing hole (32-1).
Designation (33a) denotes a pull portion defined at the forward end area of location board (3), which an operator pinches with his or her fingers and pulls upwardly in the arrow direction to start tearing the second half part (31) from the first half part (30) along the line of sewing holes (32-1, 32-2, . . . ). It is appreciated that the sewing holes (32-1, 32-2, . . . ) serves as a "tear off" perforated line to make easier the separation of the second half part (31) from the first one (30).
Turning to the sewing state of those juxtaposed three layer of central cover section (11), location board (3) and peripheral cover section (12), it should be noted from FIGS. 2 and 4 that both central and peripheral cover sections (11)(12) are in the state of being turned upside down, exposing thus their respective reverse surfaces outwardly, not their frontal surfaces, which needs to be done as described earlier for seat assembling steps, and therefore as viewed from FIG. 4, the exposed surface of peripheral cover section (12) is the reverse side thereof, whereas likewise the oppositely disposed central cover section (11) exposes its reverse side to the other outward side. Thus, in FIG. 4, the frontal surfaces respectively of those two cover sections (11) face toward each other via the location board (3).
In the practical assembling steps, the above-constructed cover member (1), as turned upside down, is placed upon the lower die (4), with the second half part (31) of location board (3) being inserted into the engagement groove (4a-1) formed in the securing portion (4a) of lower die (4), as best shown in FIG. 2. Thus, both first half part (30) of location board (3) and sewn jointed portion (1a) of cover member (1) erects upon the lower die (4). Then, when the upper die (5) is lowered towards the lower die (4), those location board first half (30) and cover member jointed portion (1a) are inserted into the recessed groove (23) of cushion member (2) mentioned above, as readily understandable from FIG. 2. As a result, the reverse surfaces of cover member (1) are bonded to the outer surfaces of cushion member (22), and then, a resultant seat is again turned upside down to attain a seat with the frontal surface of cover member (1) covering the whole outer surfaces of cushion member (2), which can be seen from FIG. 3.
Since the location board first half (31) remains projected upon such resultant seat, an operator pinches with his or her fingers the pull portion (33a) of location board (3) and pulls it upwardly, as indicated by the arrow in FIG. 3, to tear the first half part (31) from the second one (30) which is bonded in the cushion member (2), along the sewing holes (32) in the location board (3). Consequently, the assembling of seat is completed.
Although having described thus far the conventional seat assembling steps, it has yet been found as a problem that, as pointed out by designation (31a) in FIG. 3 as well as in FIG. 5, an undesired pointed projection remains uncut at the notched part (33) in the location board (3), when tearing off the first half part (31) of location board (3). This projection (31a) results in giving a hard objectionable touch or a pain to the hip of occupant sitting on the above-assembled conventional seat.
To solve this problem, one can contemplate forming the notched part (33) in a straight line or in a "V" shape, but experiments thereon reveals that, with both of those alterations, the first half part (31)f of location board (3) is not cut off along the sewing holes (32a), but easily broken away from the body of location board (3) at a quite small area generally equal to the foregoing pull portion (33a) of the same location board (3). Therefore, the U-shaped notched pat (33) as illustrated is now thought to be a best mode of tearing or cuttig introductory means for starting to tear the location board first half (31) completely away from the mating second half (30) along the sewing holes (serving as the perforated holes).